Plate holding and straining device.



No. 680,302. Patented Aug. l3, l90l.

. J. WHITE. PLATE HOLDING AND STBAINING DEVICE.

' (Application filed Dec, 14,1900.)

(No Model.) v 3 Sheets-Sheet I,

- I I Inventor:

No. 680,302. Patented Aug. l3, l90l.

' J. WHITE.

PLATE HOLDING AND STBAINING DEVICE.

(Application filed Dec. 14, 1900.)

(No Model.)

m; NoRms pmns no, morgumo, yuswmmon BC.

Paiented Aug. l3, l90l.

J. WHITE. PLATE HOLDING AND STBAINING DEVICE.

(Application filed Dec. 14, 1900.)

3 Street's-Sheet 3.

(No Model.)

m: uonms mess cov. PHDTQLITHOW'WASHINGTON, u. c.

UNITED STATES:

PATENT OFFICE.

JOSEPH \VHITE, OF NEW YORK, N. Y., ASSIGNOR TO ROBERT HOE, OF SAMEPLACE.

PLATE HOLDING AND STRAINING DEVICE.

SPECIFIGATION forming part of Letters Patent No. 680,302, dated August13, 1901.

Application filed December 14, 1900. I Serial No. 39,814. (No model.)

To aZZ whom it may concern/m Be it known that I, JOSEPH WHITE, a citizenof the United States, residing at New York, county of New York, andState ofNewYork,

have invented certain newand useful'Improvements in Plate Holding andStraining Devices, fully described and represented in the followingspecification and the accompanying drawings, forming a part of the same.

This invention relates to certain improvements in devices for strainingflexible printing-platessuch, for instance, as plates of aluminium orzinc'to their seats and holding them in strained position.

The holding and straining devices for flexible printing-plates as nowusually constructed embody a plurality of clamps mounted on a support,these clamps being independently adjustable, so that they may bemanipulated to subject different parts of the plate to greater or lessstrain, as the case may require, in or der to insure that the plate liesevenly and smoothly upon its bed. Two sets of such holding and strainingdevices are usually employed, the sets being located at opposite sidesor edges of the plate.

been adjusted by the clamps, such as have been referred to, it isfrequently found that it is not accurately positioned on its'bedthat isto say, the plate maybe toonear'one of the sets of clamps, thus beingout of register longitudinally, or too near one of the side edges of itssupport, thus being out of register laterally, or it may be askew on itssupport, thus being out of register angularly. When the sheet to beprinted is to receive but a single printing in the machine, inaccuraciesin positioning the plate may often-be compensated for by properlypositioning the sheet-r guides on the feeding-table, so that the sheetwill be fed to the machine in accordance with the position of the plateon its support. When, however, the sheet is to receive two or moreprintings in the machine-as, for instance, when it is .to be printed incolors in a single machineit is obvious that inaccuracies in positioningthe plate cannot be compensated for in the manner described. 1

It is one of the objects of this invention to produce a holding andstraining mechanism for printing machines employing flexible After aplate has printing-plates which is capacitated to effect an angularadjustment of the printing-plate with respect to its supporting-surface.

A further object of the invention is to produce a holding and strainingmechanism for printing-machines employing flexible plates which shall becapacitated to effect a lateral adjustment of the printing-plate.

A further object of the invention is to produce animproved holdingandstraining mech anism for machines employing flexible plates whichwill be capacitated to efiect a longitudinal adjustment of theprinting-plate on its snpporting-surface i. e., an adjustment in theline of strain of the holding devices for the plates.

With these and other objects in view the invention consists in certainconstructions and in certain parts, improvements, and combinations, aswill be hereinafter fully described and then specifically pointed out inthe claims hereunto appended.

In the accompanying drawings, which form a part of this specification,and in which like characters of reference indicate the same parts,Figure 1 is a front view of a part of the cylinder of a rotaryprinting-machine, the improved holding and straining devices being shownin front elevation and the cylinder being shown partly in section inorder to better illustrate some parts of the construction. Fig. 2 is anend view of a portion of the cylinder shown in Fig. 1, the direction ofthe observers view being indicated by the arrow 2 in Fig. 1. Fig. 3 is atop plan view of the construction shown in Fig. 1, part of the cylinderbeing broken away. Fig. 4 is a side elevation of the construction shownin Fig. 1, the direction of the obsert'ers view being indicated by thearrow 4 in said figure.

Referring to the drawings, which illustrate one embodiment of theinvention in which the plate-support is a cylinder rljindicates aplate-carrying cylinder of the usual-form, said cylinder being mountedon a shaft 2. The cylinder is shown as carrying a flexibleprinting-plate 3, said plate being of zinc, aluminium, or any othersuitable material. This plate is held in position upon the cylinder bysets of suitable holding and straining devices, which may be of anysuitable or desired form. Preferably, however, each set will consist ofa plurality of pairs of grippingjaws, which are or may be ofsubstantially the construction described in the patent to Thomas M.North, No. 629,916, granted August 1, 1899, to which patent reference ismade for a full description of the construction. For the purposes ofthis application it is sufficient to say that each pair of jaws embodiesa stationary jaw4 and a movable jaw 5, said jaws being forced togetherby the action of a pivoted block 6, which is moved to cause the jaws toseize or release the plate by means of a screw 7 and a wing-nut 8. Thejaws of each pair are carried on an arm 9, and the arms 9 of each setofholding and straining devices are preferably pivotally supported on arod 10, each rod being mounted in a manner to be hereinafter described.Each clamp of the set is provided with a screw 11, the screws 1.1 ofeach set of clamps operating against a suitable bearing-surface, to behereinafter described, in order to force the clamps away from the edgeof the platesupporting surface, thus straining the plate to its seat.

As has been before indicated, after the plate has been strained to itsseat by the manipulation of the clamps at opposite edges it isfrequently out of register, this fact being usually discovered byprinting a trial-sheet.

Hitherto in order to true up a plate which has been out of adjustmentangularly with respect to its supporting-surface it has been necessaryto loosen up all or the greater part of the clamps, reset the plate inthem, and readjust the clamps. By this method all the labor which hasbeen expended in straining the plate to its seat in the first instanceis lost, besides which it frequently happens that the second adjustmentleaves the plate out of register. In the improved holding and strainingdevice, therefore,means are preferably provided for adjusting the platewithout disturbing the clamps. Devices which vary widely in constructionmay be employed for effecting this angular adjustment. In the form ofconstruction shown, however, each of the supporting-rods 10 has one ofits ends mounted in a movable frame 12. This movable frame 12 is soarranged that it may be given a movement along the plate-support-- ingsurface, and when this plate-supporting surface is a cylinder, as in theconstruction shown, the movement-given the frame will be a movement inan are. To this end, in the form shown, the frame is secured to a collar13, which is mounted on the cylindershaft 2, so that the frame movesabout the cylindershaft as a center. Any suitable means may be employedfor mounting the ends of the supporting-rods 10 in the frame. As shown,however, the frame is provided with bearings 14. Bearing-screws 15 aretapped through these bearings 14,- and the inner ends of said screws arearranged to engage collars 16, the collars being swiveled on the screws.The rods 10 have their ends loosely inserted in the collars-16. By thisconstruction the rods and their collars 16 are permitted to have anangular movement with respect to the bearings 14, and at the same timethe rods are permitted to have a longitudinal movement with respect tothe collars. Theother ends of the rods 10 may be supported in anysuitable manner. In the construction shown, however, they are supportedin one of the ends of the cylinder by means which is the duplicate ofthat just described-that is to say, one of the spokes of the cylinder isprovided with bearings 17, through which are tapped screws 18, saidscrews engaging collars 19, in which the ends of the rods are looselymounted. \Vith the construction as described it will be seen that as theframe carrying one end of each of the rods 10 is moved in one directionor the other, the other end of each rod being held by the cylinder-head,the clamps on the rods and the plate held by them will be given anangular adjustment with respect to the cyl inder-surface.

Any suitable means may be employed for giving the frame 12 its movement.In the construction shown the frame 12 is provided with a rack 20, saidrack being engaged by a worm 21, mounted on a worm-shaft 22, which issupported in bearings 23, secured to the head of the cylinder.Set-screws 12, passing through slots 12" in the frame, may be used tohold the frame in position.

In order to give the plate the angular adjustment which has just beendescribed, it is desirable to release the strain which has been put uponit by the clamps, since the friction between the plate and itssupporting-surface will usually be so great as to make it impos- ICC)sible to shift the plate in its strained condition. The means forreleasing the strain on the plate without disturbing the adjustment ofthe clamps with respect to the plate may be varied widely in form andconstruction. As shown, however, movable bars 24 are provided, one sideof each of these bars forming the bearing-surface for the screws 11,there being one of these bars for each set of clamps. These bars 24 aremounted at one end in slots 25 in the frame 12, the other end of thebars being preferably supported in slots 26 in spokes of the cylinder.All the adjustingscrews 11 of each set of clamps operate against thebearing-surface 0f the bar 24 which is adjacent to that set of clamps.By moving the bars 24, therefore, away from the ends of the screws thestrain on the plate held by the clamps will be released. Any suitablemeans may be employed for giving the bars the movement referred to. Inthe construction shown, however, shafts 27 extend across the cylinderfrom side to side, these shafts being preferably provided with screwends 28, so that they may be easily turned bya wrench. The shafts 27carry worms 29, each shaft having two such worms, one near each end. The

shafts 27 are preferably mounted, so that they may be given an angularmovement corresponding to the angular adjustment of the clamp-supportingrods. WVhile the means by which the shafts are thus moved may be variedin form, in the construction shown the shafts are supported at one endin bearings 30, swiveled in brackets 31, extending from one of thespokes of the cylinder. At the other end these shafts are supported inbearings 32, swiveled in the frame 12. Located in suitable bearings 34in the frame 12 are screws 35, bearing at one.end against the bars 24and having on their other ends wormgears 36, which engage two of theworms 29. Similar screws 37, tapped in bearings 38 at the other end of.the cylinder, bear against the other end of the bars 24, said screwshaving worm-gears 39, which engage the other worms 29. With thisconstruction it will be seen that when the shafts 27 are rotated in theproper direction the bearing-bars 24 will be allowed to move away fromthe ends of the screws 11, thus releasing the strain on the plate. Whenthe strain is thus released, the angular adjustment before referred tomay be effected by the movement of the frame 12, after which a reversemovement of the shafts will cause thebars 24 to, move up into properposition to again strain the plate to its seat. It will be noted that bythis construction the angular adjustment of the plate is effectedwithout in any way disturbing the adjustment of the plate-clamps withrespect to the plate. If, therefore, the plate has been properlystrained to its seat in the first instance, by the operation of theclamps, the rotation of the shafts 27in the proper direction, after theadjustment has been effected, will bring the plate back onto its seatproperly strained, as in the first instance. Should it be desired tomove the plate longitudinally of its supporting-surface, or,when thesupporting-surface is a cylinder, circnmferentially, this can be readilyand quickly effected by manipulation of the bearing-bars 24, since byslacking up the bearing-screws 35 37 for one of the bars and tighteningup the bearing-screws for the other bar the plate will be shifted bodilycircumferentially of the surface. Furthermore, by mounting thebearing-surface, as in the present construction, independently of theplate-clamps a simple and compact device is obtained, and one in whichavery considerable circumferential or longitudinal adjustment of theplate can be effected. Furthermore, within its limits this adjustmentmay be as fine as is necessary to exactly position the plate. Theconstructiouis therefore superior to other devices in the art in whichthe longitudinal adjustment of the plate is effected by a movement ofthe support on which the plate-clamps are carried. 1n the better classof these devices the adjustment is effected by means of a ratchet orother similar device by which the plate is given successive movementseach of a definite extent, and the fineness of the adjustment dependsupon the length of each successive movement.

In addition to the adjustments before referred to the holding andstraining devices are also preferably constructed so that the platemaybe given alateral adjustmentthat is, an adjustment at right angles tothe line of strain produced by said devices. The means by which thislateral adjustment is efiected may Vary within wide limits. In theconstruction shown each of the supportingrods 10 is provided withcollars 40, said collars being engaged by pins 41 on a cross-bar 42.This cross-bar 42 is secured by a suitable screw 43 to a sliding block44, moving in suitable ways in a guiding-block 45. The block 45 isprovided with a threaded car 46, which is engaged by a screw 47, mountedin a bearing 48 in thecylinder-head, said screw carrying a hand-wheel orother adjusting means 49. It is obvious that by rotating the hand-wheelthe bar 42 will be moved forward or backward and will carry with it therods 10. Before effecting this adjustment the strain on the plate willbe released in the manner hereinbefore described.

Suitable means are provided in order to insure that the clamps move whentheir supporting-rods are moved longitudinally in the manner described.While these means may vary in construction, as shown, the arms 9 arebifurcated at their lower ends and are arranged to straddle collars 50,secured to the shaft by set-screws 51, or in any other suitable manner.I

It will be understood that the devices by which the invention is carriedinto effect may be varied within wide limits. The invention is not,therefore, to be limited to the specific details of construction whichhave been hereinbefore described. WVhile, furthermore, the

invention is especially adapted for use with I respect to the surfacewhile holding the plate,

substantially as described.

2. The combination with a cylindrical platesupporting surface, ofdevices for holding a plate in position thereon, and means for givingsaid holding devices an angular adjustment with respect to the surfacewhile holding the plate, substantially as described.

3. The combination with a plate-supporting surface, of devices forholding a plate in position thereon, and means for giving said holdingdevices a lateral adjustment with re I spect to the surface whileholding the 4. Thecombination with a cylindrical platesupportingsurface, of devices for holding a plate in position thereon, and meansfor giving said holding devices a lateral adjustment With respect to thesurface while holding the plate, substantially as described.

5. The combination with a plate-supportin g surface,of devices forholding a plate in position thereon, means for giving said holdingdevices an angular adjustment with respect to the surface while holdingthe plate, and means for giving said devices a lateral adjustment,substantially as described.

6. The combination with a cylindrical platesupporting surface, ofdevices for holding a plate in position thereon, means for giving saidholding devices an angular adjustment with respect to the surface whileholding the plate, and means for giving said devices 2.- lateraladjustment, substantially as described.

7. The combination with a plate-supporting surface, of devices forholding a flexible plate in position thereon, means for adjusting saiddevices to strain the plate to its seat, means for releasing the strainon the plate, and means for giving said holding devices while holdingthe plate an angular adjustment with respect to the supporting-surface,substantially as described.

8. The combination withacylindrical platesupporting surface, of devicesfor holding a flexible plate in position thereon, means for adjustingsaid devices to strain the plate to its seat, means for releasing thestrain on the plate, and means for giving said holding devices whileholding the plate an angular adjustment with respect to thesupporting-surface, substantially as described.

9. The combination with a plate-supporting surface, of devices forholding a flexible plate in position thereon, means for adj usting saiddevices to strain the plate to its seat, means for releasing the strainon the plate, and means for giving said holding devices while holdingthe plate a lateral adjustment with respect to the supporting-surface,sub stantially as described.

10. The combination with a cylindrical plate-supporting surface, ofdevices for holding a flexible plate in position thereon,means foradjusting said devices to strain the plate to its seat, means forreleasing the strain on the plate, andmeans for giving said holdingdevices while holding the plate a lateral adjustment with respect to thesupporting-surface, substantially as described.

11. The combination with a plate-supporting surface, of a bearingsurface, plate-holding devices, means carried by the devices andoperating against said surface to strain the plate to its seat,1neansfor adj usting the bearing-surface to release the strain on the plate,and means for giving the holding devices while holding the plate anangular adjustment with respect to the supporting-surface, substantiallyas described.

12. The combination with a cylindrical ing-surface to release the strainon the plate,

and means for giving the holding devices while holding the plate alateral adjustment with respect to the supporting-surface, substantiallyas described.

14:- The combination with a cylindrical plate-supporting surface, of abearing-surface, plate-holding devices, means carried by the devices andoperating against said surface to strain the plate to its seat, meansfor adjusting the bearing-surface to release the strain on the plate,and means for giving the holding devices while holding the plate alateral adjustment with respect to the supporting-surface, substantiallyas described.

15. The combination with a plate-supporting surface, of devices forholding a plate in position thereon,a bearing-surface supportedindependently of the holding devices, means carried by the holdingdevices and operating against said surface to strain the plate to itsseat, and means for adjusting the bearingsurface, substantially asdescribed.

16. The combination with a cylindrical plate-supporting surface, ofdevices for holding a plate in position thereon, a bearing-surfacesupported independently of the holding devices, means carried by theholding devices and operating against said surface to strain the plateto its seat, and means for adjustin g the bearing-surface, substantiallyas described. I

17. The combination with a plate-supporting surface, of holding deviceslocated at opposite edges of the. plate, bearing-surfaces, one for eachholding device, said surfaces being supported independently of theholding devices, means carried by said devices and operating against thebearing-surfaces to strain and hold the plate on the supportingsurface,and means for adjusting the bearingsurfaces,substantially as described.

18. The combination with a cylindrical plate-supporting surface, ofholding devices located at opposite edges of the plate,bearing-surfaces, one for each holding device, said surfaces beingsupported independently of the holding devices, means carried by saiddevices and operating against the bearingsurfaces to strain and hold theplate on the supporting-surface, and means for adjusting the bearingsurfaces, substantially as de scribed.

19. The combination with a plate-supporting surface, of holding deviceslocated at opposite edges of the plate, bearing-surfaces, one for eachholding device, said surfaces being supported independently of theholding devices, means carried by said devices and operating against thebearing-surfaces to strain and hold the plate on the supportingsurface,and means for giving the holding devices while holding the plate and thebearingsurfaces an angular adj ustment,substantial]y as described.

20. The combination with a cylindrical plate-supporting surface, ofholding devices located at opposite edges of the plate,bearing-surfaces, one for each holding device, said surfaces beingsupported independently of the holding devices, means carried by saiddevices and operating against the bearingsurfaces to strain and hold theplate on the supporting-surface, and means for giving the holdingdevices while holding the plate and the bearing-surfaces an angularadjustment, substantially as described. I

21. The combination with a plate-supporting surface, of holding deviceslocated at opposite edges of the plate, bearing-surfaces, one for eachholding device, said surfaces being supported independently of theholding devices, means carried by said devices and operating against thebearing surfaces to strain and hold the plate on the supportingsurface,and means for giving the holding devices while holding the plate and thebearingsurfaces a lateral adjustment, substantially as described.

22. The combination with a cylindrical plate-supporting surface, ofholding devices located at opposite edges of the plate,bearing-surfaces, one for each holding device, said surfaces beingsupported independently of the holding devices, means carried by saiddevices and operating against the bearingsurfaces to strain and hold theplate on the supporting-surface, and means for giving the holdingdevices while holding the plate and the bearing-surfaces a lateraladjustment, substantially as described.

23. The combination with a plate-supporting surface, of holding deviceslocated at opposite edges of the plate, bearing-surfaces, one for eachholding device, said surfaces being supported independently of theholding devices, means carried by said devices and operating against thebearing-surfaces to strain and hold the plate on the supportingisurface, means for adjusting the bearing-surfaces, means for giving theholding devices while holding the plate and the bearing-surfaces anangular adjustment, and means for 1 giving the holding devices whileholding the plate and the bearing-surfaces a lateral ad- 1 jiistment,substantially as described.

2i. In a plate-holding device, the combination with a plate-supportingsurface, ofa plurality of pairs of gripping-jaws, means for operatingeach pair of jaws to cause them to seize and release the plate, abearing-surface supported independently of the pairs of jaws, meanswhereby each pair of jaws may be adj usted with respect to thebearing-surface to strain the plate to its seat, and means for adjustingthe bearing-surface, substantially as described.

25. In a plate-holding device, the combination with a plate-supportingsurface, of a plurality of pairs of pivoted gripping-jaws,means foroperating each pair of jaws to cause them to seize and release theplate, a bearing-surface supported independently of the pairs of jaws,means whereby each pair of jaws may be adjusted with respect to thebearing-surface to strain the plate to its seat, and means for adjustingthe bearing-surface, substantially as described.

26. The combination with a plate-supporting surface, of a plurality ofpairs of gripping-jaws, means for causing said jaws to clamp and releasethe plate, a support upon which the jaws are mounted, and means forgiving the jaws and the support an angular adjustment with respect tothe supportingsurface, substantially as described.

27. The combination with a plate-support ing surface, of 'a plurality ofpairs of pivoted gripping-jaws, means for causing said jaws to clamp andrelease the plate, a support upon which the jaws are mounted, and meansfor giving the jaws and the support an angular adjustment with respectto the supporting-surface, substantially as described.

28. The combination with a plate-supporting surface, of a plurality ofpairs of gripping-jaws, means for causing said jaws to clamp and releasethe plate, a support upon which the jaws are mounted,"and means forgiving the jaws and the support a lateral adjustment with respect to thesupporting-surface, substantially as described.

29. The combination with a plate-supporting surface, of a pluralityofpairs of pivoted gripping-jaws, means for causing said jaws to clamp andrelease the plate, a support upon which the jaws are mounted, and meansfor giving the jaws and the support a lateral adjustment with respect tothe supporting-surface, substantially as described.

30. The combination with a plate-supporting surface, of a plurality ofpairs ofgrippingjaws, means for causing said jaws to grip and releasethe plate, a supporton which said jaws are mounted, a bearing-surface,means for forcing the pairs of jaws away from the bearing-surface inorder to strain the plate to its seat, and means for giving the supportsand the bearing-surface an angular adjustment with respect to theplate-supporting surface, substantially as described.

31. The combination with a plate-support ing surface, of a plurality ofpairs of pivoted gripping-jaws, means for causing said jaws to grip andrelease the plate, a support on which said jaws are mounted, abearing-surface, means for forcing the pairs of jaws away from thebearing-surface in order to strain the plate to its seat, and means forgiving the supports and the bearing-surface an angular adjustment withrespect to the plate-supporting surface, substantially as described.

32. The combination with a plate-supporting surface, ofa plurality ofpairs of grippingjaws, means for causing said jaws to grip and releasethe plate, a support on which said jaws are mounted, a bearing-surface,means for forcing the pairs of jaws away from the bearing-surface inorder to strain the plate to its seat, and means for giving the supportsand the bearing-surface a lateral adjustment with respect to theplate-supporting surface, substantially as described.

33. The combination with a plate-supporting surface, of a plurality ofpairs of pivoted gripping-jaws, means for causing said jaws to grip andrelease the plate, a support on which said jaws are mounted, abearing-surface, means for forcing the pairs of jaws away from thebearing-surface in order to strain the plate to its seat, and meansforgiving the supports and the bearing-surface a lateral ad-- justmentwith respect to the plate-supporting surface, substantially asdescribed.

34. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plu rality of pairs of gripping-jaws, a support for thejaws of each set, means for causing each pair of jaws to clamp andrelease the plate, means for forcing each pair of jaws away from thesurface in order to strain the plate to its seat,

and means for giving each set of jaws and the support therefor anadjustment with respect to the supporting-surface, substantially asdescribed.

85. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of gripping-jaws, a support for thejaws of each set, means for causing each pair of jaws to clamp andrelease the plate, means for forcing each pair of jaws away from thesurface in order to strain the plate to its seat, and means for givingeach set of jaws and the support therefor an angular adjustment withrespect to the surface, substantially as described.

36. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of pivoted gripping-jaws, a supportfor the jaws of each set, means for causing each pair of jaws to clampand release the plate, means for forcing each pair of jaws away from thesurface in order to strain the plate to its seat, and means for givingeach set of jaws and the support therefor an angular adjustment withrespect to the surface, substantially as described.

38. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of gripping-jaws, a support for thejaws 'of each set, means for causing each pair of jaws to clamp andrelease the plate, means for forcing each pair of jaws away from thesurface in order to strain the plate to its seat, means for giving eachset of jaws and the support therefor an angular adjustment with respectto the surface, and means for giving the sets of jaws a lateraladjustment, substantially as described.

39. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the sur face, eachset including a plurality of pairs of pivoted gripping-jaws, a supportfor the jaws of each set, means for causing each pair of jaws to clampand release the plate, means for forcing each pair of jaws away from thesurface in order to strain the plate to its seat, means for giving eachset of jaws and the support therefor an angular adjustment with respectto the surface, and means for giving the sets of jaws a lateraladjustment, substantially as described.

40. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the sur- 'face, eachset including a plurality of pairs of gripping-jaws, a support for thejaws of each set, means for causing each pair of jaws to clamp andrelease the plate,-bearing-surfaces, means carried by each pair of jawsfor forcing the jaws awayfrom said surfaces, and means for giving eachset of jaws, the support therefor and the cooperating bearingsurface anadjustment with respect to the plate-supportin g surface, substantiallyas described.

41. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the'surface, eachset including a plurality of pairs of gripping-jaws, a support for thejaws of each set, means for causing each pair of jaws to clamp andrelease the plate, bearing-surfaces, means carried by each pair of jawsfor forcing the jaws away from said surfaces, andmeans for giving eachset of jaws, the support therefor and the cooperating bearingsurface anangular adjustment with respect to the plate-supportin g surface,substantially as described.

IIO

42. The combination with aplate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset. including a plurality of pairs of pivoted gripping-jaws, a supportfor the jaws of each set, means for causing each pair of jaws to clampand release the plate, bearing-surfaces, means carried by each pair ofjaws for forcing the jaws away from said surfaces, and means for givingeach set of jaws, the support therefor and the cooperatingbearing-surface an adjustment with respect to the plate-supportingsurface, substantially as described.

43. The combination with a plate-support ing surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of pivoted gripping-jaws, a supportfor the jaws of each set, means for causing each pair of jaws to clampand release the plate, bearing-surfaces, means carried by each pair ofjaws for forcing the jaws away from said surfaces, and means for givingeach set of jaws, the support thereforand the cooperatingbearing-surface an angular adjustment with respect to theplate-supporting surface, substantially as described.

44. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of gripping-jaws, a support for thejaws of each set, means for causing each pair of jaws to clampandrelease the plate, bearing-surfaces, means earried by each pair ofjaws for forcing the jaws away from said surfaces, and means for givingeach set of jaws, the support therefor and the cooperatingbearingsurface a lateral adjustment with respect to the plate-supportingsurface, substantially as described.

45. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset i-ncluding a plurality of pairs of pivoted gripping-jaws, a supportfor the jaws of each set, means for causing each pair of jaws to clampand release the plate, bearing-surfaces, means carried by. each pair ofjaws for'forcing the jaws away from said surfaces, and means for givingeach set of jaws, the support therefor and the cooperatingbearing-surface a lateral adjustment with respect to theplate-supporting surface, substantially as described.

4 d. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of gripping-jaws, a support for thejaws of each set, means for causing each pair of jaws to clamp andrelease the plate, bearing-surfaces, means carried by each pair of jawsfor forcing the jaws away from the bearing-surfaces, means for givingeach set of jaws, the support therefor and the cooperatingbearing-surface an angular adjustment with respect to theplate-supporting surface, and means for giving each set of jaws, thesupport therefor, and the cooperating bearing-- surface a lateraladjustment with respect to the plate-supporting surface, substantiallyas described.

47. The combination with a plate-supporting surface, of sets of holdingand straining devices arranged at opposite edges of the surface, eachset including a plurality of pairs of pivoted gripping-jaws, a supportfor the jaws of each set, means for causing each pair of jaws to clampand release the plate, bearing-surfaces, means carried by each pair ofjaws for forcing the jaws away fromthe bearing-surfaces, means forgiving each set of jaws, the support thereforand the cooperatingbearing-surface an angular adjustment with respect to theplate-supporting surface, and means for giving each set of jaws, thesupport therefor, and the cooperating bearingsurface a lateraladjustment with respect to the plate-supporting surface, substantiallyas described.

48. The combination with a plate-support- .ing surface, of a frame,means for moving the frame along the surface, a pair of supports,

one end of each support being mounted in the frame, straining devicespivoted on each support, means for causing said devices to seize andrelease the plate, and means for causing said devices to strain theplate over the surface, substantially as described. A

50. The combination with a plate-supporting surface, of a frame, meansfor moving the frame along the surface, a pair of supports,

one end of each support being mounted in the frame, a pair ofbearing-surfaces, one end of each bearing-surface being mounted in theframe, holding and straining devices mounted on each support, means forcausing said devices to seize and release the plate, and means foradjusting the bearing-surfaces, substantially as described.

51. The combination with a plate-supporting surface, a frame, means formoving the frame along the surface, a pair of supports,

one end of each support being mounted in the frame, a pair ofbearing-surfaces, one end of each bearing-surface being mounted in theframe, holding and straining devices pivoted on each support, means forcausing said devices toseize and release the plate, and means foradjusting the bearing-surfaces, substantially as described.

52. The combination with a cylindrical plate-supporting surface, of aframe, means devices pivoted on each support, means for causing saiddevices to seize and release the plate, and means for causing saiddevices to strain the plate over the surface, substantially asdescribed.

54. The combination with a cylindrical plate-supporting surface, of aframe, means for giving the frame a movement in an are, a pair ofsupports, one end of each support being mounted in the frame, a pair ofbearingsurfaces,one end of each surface being mounted in the frame,holding and straining de vices mounted on each support, means forcausing said devices to seize and release the plate, and means foradjusting the bearingsurfaces, substantially as described.

55. The combination with 'a cylindrical plate-supporting surface, of aframe, means for giving the frame a movement in an are, a pair ofsupports, one end of each support being mounted in the frame, a pair ofbearingsurfaces,one end of each surface being mount ed in the frame,holding and straining devices pivoted on each support, means for causingsaid devices to seize and release the plate, and means for adjusting thebearin g-surfaces, substantially as described.

56. The combination with a cylinder having a plate-supporting surface,of a frame supported on the cylinder-shaft, means for giving the frame amovement about the shaft, a pair of supports, one end of each supportbeing mounted in the frame, a plurality of straining devices mounted oneach support, means for causing each pair of straining devices to gripand release the plate, and means for giving the straining devices amovement to strain the plate to its seat, substantially as described. 7

57. The combination with a cylinder having a plate-supporting surface,of a frame supported on the cylinder-shaft, means for giving the frame amovement about the shaft, a pair of supports, one end of each supportbeing mounted in the frame, a plurality of straining devices pivoted oneach support, a pair of bearing-surfaces, one end of eachbearing-surface being mounted in the frame, and means for giving eachbearing-surface a bodily adjustment, substantially as described.

58. The combination With a plate-supporting surface, of sets ofstraining devices located at opposite edges thereof, means for causingthe straining devices to seizeand release the plate, a bearing-bar foreach set of devices,. means cooperating with the bars whereby eachstraining device ofeach set may be operated to strain the plate to itsseat, a shaft adjacent to each bar, and means operated by the shafts foradjusting the bearingbars with respect to the straining devices,substantially as described.

59. The combination with a cylinder having a plate-supporting surface,of a frame, means for giving the frame a movement in an are, a supportat eachend of the frame, each support having one end mounted'in theframe and the other end mounted in the cylinder, a plurality of plateclamps mounted on each support, means for causing said clamps to seizeand release the plate, a bearing-bar at each end of the frame,ione endof each bar being mounted intheframe and the other end being mounted inthe cylinder, means for giving each bar a bodily adjustment, and meanscooperating with the bars whereby each clamp-is caused to strain theplate to its seat, substantially as described.

60. The combination with a cylinder having a plate-supporting surface,of a frame, means for giving the frame a movement in an are, a supportateach end of the frame, each support having one end mounted in theframe and the other end mounted in the cylinder, a plurality ofplate-clamps pivoted on each support, means for causing said clamps toseize and release the plate, a bearing-bar at each end of the frame, oneend of each bar being mounted in the frame and the other end beingmounted in the cylinder, means for giving each bar a bodily adjustment,and means cooperating with the bars whereby each clamp is caused tostrain the plate to its seat, substantially as described.

61. The combination Withacylinderhaving a plate-supporting surface, of aframe, means for giving the frame a movement in an are, a support ateach end of the frame, each support having one end mounted in the frameand the other end mounted in the cylinder, a plurality of plate-clampspivoted on each support, means for causing said clamps to seize andrelease the plate, a bearing-bar at each end of the frame, one end ofeach bar being mounted in the frame and the other end being mounted inthe cylinder, shafts extending across the cylinder adjacent to the bars,Worms on the shafts, suitably-mounted screws driven by the Worms andbearing against the bars, whereby the bars are bodily adjusted,

and means cooperating with the bars Whereby each clamp is caused tostrain the plate to its seat, substantially as described.

62. The combination With a cylinder having a plate-supporting surface,of sets of plateclamps at opposite edges of the surface, supporting-rodson which the clamps are mounted, means for causing the clamps to seizeand release the plate and to strain the plate to its seat, and means forgiving the rods and the clamps mounted on them a lengthwise adjustment,substantially as described.

63. The combination with a cylinder having a plate-supporting surface,of sets of plateclamps at opposite edges of the surface, supporting-rodson which the clamps are pivoted, means for causing the clamps to seizeand release the plate and to strain the plate to its seat, and means forgiving the rods and the clamps mounted on them a lengthwise adj ustment,substantially as described.

6%. The combination with a cylinder having a plate-supporting surface,of sets of plateclamps at opposite edges of the surface, supporting-rodson which the clamps are pivoted,

means for causing the clamps to seize and release the plate and tostrain the plate to its seat, and means for giving the rods and theclamps mounted on them a simultaneous adjustment, substantially asdescribed.

65. The combination with a cylinder having a plate-supporting surface,of sets of plateclamps at opposite edges of the'surface, rods on whichthe sets of clamps are pivoted, a bar supported in the cylinder,connections between the ends of the bar and the rods, and

means for moving the bar to give the rods a lengthwise adjustment,substantially as described.

66. The combination with a cylinder having a plate-supporting surface,of a frame, means for giving the frame a movement in the arc of acircle, a set of plate-clamps at each end of the surface, rods on whichthe clamps are pivoted, one end of said rods being mounted in the frameand the other end in the cylinder, bearing-bars one for each set ofclamps, one end being mounted in the frame and the other end in thecylinder, means for causing 40 the clamps to seize and release theplate, means cooperating with the bearing-bars for causing the clamps tostrain the plate against the supporting-surface, means for giving thebearing-bars a bodily adjustment, and means for giving thesupporting-rods a longitudinaladjustment, substantially as described.

67. The combination with a cylinderhaving a plate-supporting surface, ofa frame, means for giving the frame a movement in the are of a circle, aset of plate-clamps at each end of the surface, rods on which the clampsare pivoted, one end of said rods being mounted in the frame and theother end in the cylinder, bearing-bars one for each set of clamps,

bearing-bars for causing the clamps to strain the plate against thesupporting-surface, shafts mounted in the cylinder adjacent to thebearing-bars, means driven by the shafts for bodily adjusting the bars,and means for giving the supporting-rods a longitudinal adjustment,substantially as described.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

JOSEPH WHITE.

Witnesses:

F. W. H. CRANE, L. RoEHM.

